Experimental performance evaluation and validation of dynamical contact models of the Ocean Grazer

A functional scale prototype has been constructed for a single-piston pump (SPP) that will be used as a building block in the core technology of a novel wave energy converter termed the Ocean Grazer: the multi-pump, multi-piston power take-off (MP²PTO) system. Experimental measurements performed with this scale prototype show that volumetric losses in the pumping system dictate its total efficiency, defined as the product of the volumetric and mechanical efficiencies. The mechanical efficiency alone is found to be as high as 99%. Furthermore, these measurements provide excellent validation for developed mathematical models, not only in regards to the predicted mechanical efficiency, but also when comparing the experimentally measured and numerically calculated kinematics, forces and pressures in the system.